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The enantioselective 1,3-dipolar cycloaddition of nitrones and arylpropionaldehydes to generate highly functionalized scaffolds for application in drug discovery was herein investigated. The use of a second-generation MacMillan catalyst as hydrochloride salt consistently accelerated the reaction speed, allowing a decrease in the reaction time up to >100 times, still affording 4-isoxazolines with good to excellent enantiomeric ratios at room temperature. As a proof of concept, further functionalization of the isoxazoline core through Pd-catalyzed cross-coupling was performed, generating differently functionalized chemical architectures in high yield.

A fast and greensolution-phase peptide synthesis (GSolPPS) via continuous protocol, addressed with propylphosphonic anhydride T3P® as coupling reagent and N-benzyloxycarbonyl-protecting group easily removed by hydrogenation is herein reported.

Developing greener synthesis processes is an inescapable necessity to transform the industrial landscape, mainly in the pharmaceutical sector, into a long-term, sustainable reality. In this context, the renaissance of peptides as medical treatments, and the enforcement of more stringent sustainability requirements by regulatory agencies, pushed chemists toward the introduction of sustainable processes to prepare highly pure, active pharmaceutical ingredients (APIs). Innovative upstream (synthesis) and downstream (purification) methodologies have been developed during the last 5 years with the introduction and optimization of several technologies in solid-phase peptide synthesis (SPPS), liquid-phase peptide synthesis (LPPS), chemoenzymatic peptide synthesis (CEPS), and chromatographic procedures. These innovations are also moving toward the introduction of continuous processes that represent one of the most important targets for iterative processes. This overview discusses the most recent efforts in making peptide chemistry greener. The extensive studies that were carried out on green solvents, reaction conditions, auxiliary reagents and purification technologies in the peptide segment can be useful to other fields of organic synthesis

The identification of a green, versatile, user‐friendly, and efficient methodology is necessary to facilitate the use of Heck‐Cassar‐Sonogashira (HCS) cross‐coupling reaction in drug discovery and industrial production in the pharmaceutical segment. The Heck‐Cassar and Sonogashira protocols, using N‐hydroxyethylpyrrolidone (HEP)/water/N,N,N′,N′‐tetramethyl guanidine (TMG) as green solvent/base mixture and sulfonated phosphine ligands, allowed to recycle the catalyst, always guaranteeing high yields and fast conversion under mild conditions, with aryl iodides, bromides, and triflates. No catalyst leakage or metal contamination of the final product were observed during the HCS recycling. To our knowledge, a turnover number (TON) up to 2375, a turnover frequency (TOF) of 158 h−1, and a process mass intensity (PMI) around 7 that decreased around 3 after solvent, base, and palladium recovery, represent one of the best results to date using a sustainable protocol. The Heck‐Cassar protocol using sSPhos was successfully applied to the telescoped synthesis of Erlotinib (TON: 1380; TOF: 46 h−1)., Recycle and reuse: Heck‐Cassar‐Sonogashira cross‐coupling using the green N‐hydroxyethylpyrrolidone (HEP)/H2O/N,N,N′,N′‐tetramethyl guanidine (TMG) blend, sulfonate phosphines, and aryl iodides, bromides, and triflates affords the corresponding products in high yield free from metal contamination. The catalyst/HEP/H2O solution can be recycled, increasing turnover number and frequency up to 2375 and 158 h−1, respectively, with a low process mass intensity close to 3 after solvent, base, and palladium recovery. Additionally, Erlotinib synthesis is described.

Solid Phase Peptide Synthesis (SPPS) is a key technology for the production of pharmaceutical grade peptides, although it represents the worst modality in the pharma segment when considering its Process Mass Intensity (PMI). Consequently, academic and industrial research teams have focused their attention on greening SPPS protocols by introducing more sustainable alternatives to the most common reagents and solvents. In this context, 3-(diethylamino)propylamine (DEAPA) was identified to be a viable alternative to piperidine for Fmoc removal. In addition, the use of DEAPA in N-octyl-pyrrolidone (manual synthesis) or N-octyl pyrrolidone/dimethyl carbonate 8/2 v/v (automated synthesis) was proved to be able to minimize the formation of side products like diastereoisomers and aspartimide-containing derivatives.

Targeting protein-protein interactions (PPIs) has been recently recognized as an emerging therapeutic approach for several diseases. Up today, more than half a million PPI dysregulations have been found to be involved in pathological events. The dynamic nature of these processes and the involvement of large protein surfaces discouraged anyway the scientific community in considering them promising therapeutic targets. More recently peptide drugs received renewed attention since drug discovery has offered a broad range of structural diverse sequences, moving from traditionally endogenous peptides to sequences possessing improved pharmaceutical profiles. About 70 peptides are currently on the marked but several others are in clinical development. In this review we want to report the update on these novel APIs, focusing our attention on the molecules in clinical development, representing the direct consequence of the drug discovery process of the last 10 years. The comprehensive collection will be classified in function of the structural characteristics (native, analogous, heterologous) and on the basis of the therapeutic targets. The mechanism of interference on PPI will also be reported to offer useful information for novel peptide design.

The investigation of new green biogenic pyrrolidinones as alternative solvents to N,N-dimethylformamide (DMF) for solid phase peptide synthesis (SPPS) led to the identification of N-octyl pyrrolidone (NOP) as the best candidate. NOP showed good performances in terms of swelling, coupling efficiency and low isomerization generating peptides with very high purity. A mixture of NOP with 20% dimethyl carbonate (DMC) allowed a decrease in solvent viscosity, making the mixture suitable for the automated solid-phase protocol. Aib-enkephalin and linear octreotide were successfully used to test the methodologies. It is worth noting that NOP, DMC and the piperidine used in the deprotection step could be easily recovered by direct distillation from the process waste mixture. The process mass intensity (PMI), being reduced by 63–66%, achieved an outstanding value representing a clear step forward in achieving green SPPS.

Starting from six potential hits identified in a virtual screening campaign directed to a cryptic pocket of BACE-1, at the edge of the catalytic cleft, we have synthesized and evaluated six hybrid compounds, designed to simultaneously reach BACE-1 secondary and catalytic sites and to exert additional activities of interest for Alzheimer's disease (AD). We have identified a lead compound with potent in vitro activity towards human BACE-1 and cholinesterases, moderate Aβ42 and tau antiaggregating activity, and brain permeability, which is nontoxic in neuronal cells and zebrafish embryos at concentrations above those required for the in vitro activities. This compound completely restored short- and long-term memory in a mouse model of AD (SAMP8) relative to healthy control strain SAMR1, shifted APP processing towards the non-amyloidogenic pathway, reduced tau phosphorylation, and increased the levels of synaptic proteins PSD95 and synaptophysin, thereby emerging as a promising disease-modifying, cognition-enhancing anti-AD lead.

Ampicillin, discovered in 1958, was the first broad spectrum semisynthetic penicillin introduced into the market. Despite its wide use not all the impurities have been identified to date. Herein, the last unknown impurity present in commercially available medicines was isolated and identified. This impurity that accounts up to 0.8 in area % by HPLC (EP 10.0) in the Reference Listed Drugs (RLD) was characterized and identified to be the 16-keto penicillin G. The structure was confirmed by comparison with a chemically synthesized sample. The determination of the Relative Response Factor (RRF) of the impurity respect to the parent drug allowed to recalculate the real amount that is consistently below the reporting threshold.

Malagasy adolescents face severe challenges in accessing and completing basic education. Among those students who complete the primary cycle, one in four does not transition into lower secondary school. Economic constraints among vulnerable households coupled with low-quality education result in widespread dropout and poor learning outcomes. Acknowledging these multidimensional barriers, UNICEF Madagascar leveraged funds from the Let us Learn (LUL) programme to implement a two-pronged strategy to support Malagasy children in accessing and continuing lower secondary school. The Catch-up Classes provide out-of-school adolescents with a learning pathway to build the foundational literacy and numeracy skills they need to resume studying in formal school. Conditional cash transfers target families with children who are at risk of abandoning school after completing the primary cycle. This brief builds on programme monitoring data, impact evaluations and qualitative insights from the field to highlight lessons learnt and actionable recommendations for accessing and continuing vulnerable children’s secondary education.

This working paper identifies and explores the issues that should be considered when undertaking ethical research involving children in humanitarian settings. Research grounded in sound ethical principles is critical in ensuring that children’s rights are respected throughout the process and beyond and that the research itself is relevant, useful and valid. This paper examines both the universal (i.e. relevant to all research involving children) and specific ethical issues that may arise when involving children in research in humanitarian settings. This is undertaken through an examination of the literature, a review of relevant case studies and a reflection on the ethical issues highlighted in UNICEF’s Procedure for Ethical Standards in Research, Evaluation, Data Collection and Analysis (the Ethics Procedure). The latter is used as a baseline for generic ethical standards when involving children in research.

This working paper identifies and explores the issues that should be considered when undertaking ethical research involving children in humanitarian settings. Research grounded in sound ethical principles is critical in ensuring that children’s rights are respected throughout the process and beyond and that the research itself is relevant, useful and valid. This paper examines both the universal (i.e. relevant to all research involving children) and specific ethical issues that may arise when involving children in research in humanitarian settings. This is undertaken through an examination of the literature, a review of relevant case studies and a reflection on the ethical issues highlighted in UNICEF’s Procedure for Ethical Standards in Research, Evaluation, Data Collection and Analysis (the Ethics Procedure). The latter is used as a baseline for generic ethical standards when involving children in research. The key findings of this overview highlight that many of the ethical issues that are present in other settings remain relevant and applicable in the context of humanitarian settings. These ethical issues include: an institution’s capacity to appropriately and respectfully engage children in research, understanding power relations, securing informed consent and assent, ascertaining harms and benefits, maintaining privacy and confidentiality, and ensuring appropriate communication of findings.